season is over and after the young have been born, the 

 male will, if he has the opportunity, kill the young. 

 In such cases the female drives the male away and does 

 not permit him to linger about the nest after the young 

 have been born. 



The courting habits of both sexes in all animal 

 groups are always interesting to observe, as is shown 

 in the courting of birds, for instance. Frequently the 

 male is larger, more powerful, and better ee^uipped for 

 protection than the female. As in birds, the male often 

 has a more brilliant color and sometimes he has addi- 

 tional structures which are of purely secondary sexual 

 character. In birds these structures are spurs, long 

 tail feathers, crests, etc. In the peacock, for example, 

 the large fan-shaped tail of brilliantly marked feathers 

 that distinguishes the male from the female is a second- 

 ary sexual adornment. In mammals these structures 

 may be extra hair tufts, a longer and more bushy tail, 

 larger and longer canine teeth, long horns, etc. Some- 

 times mammals have scent glands and other means by 

 which they are able to find one another, and "calling" 

 is a common method of attraction. 



There are some mammals that live singly, or in 

 pairs. Others live in colonies. Some, like the Wolves, 

 travel and hunt in great packs, in order that they may 

 unite in "bringing down" larger animals. These forms 

 however, do not usually manifest a very great amount 

 of altruism and, after killing a victim, they will often 

 indulge in greedy fights over the carcass. Cattle and 

 horses, as well as other gregarious animals, travel also 

 in herds, chiefly for mutual protection. In a beaver 

 colony all of the members will work together in per- 



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